Purification of hydrochloric-acid gas.



UN TE STATES PATENT OFFICE.

WILHE-L'MHASENBACH, OF MANNHEIM, GERMANY.

PURIFICATIONIOF, HYDROCHLORlO-ACID GAS.

To all whom; it may concern:

Be it known. that I, WILHELM'HASENBACH, a subject of the German Emperor, residing at Mannhe m, Germany, have invented certain new and useful Improvements in the Purification of Hydroch oric-Acid Gas, of which the'following is a specification.

' considerable difficulties.

Our invention relates to improvements in the purification of the hydrochloricacid gases, whereby this purification is ,exceedingl simplified and cheapened.

I 's invention is base on the discovery that vaporous chloride of arsenic are absorbed by oils with a great energy., Now that the said hydrochloric-acid gases contain as impurities arsenic in the sha e of chlorids, it is evident that they can be freed from their in'urious arsenicby washing them with an oil. Al so the other impurities of the commercial hydrochloric-acid gases-such as, for instance, sulfuric acid-are retained by the oil. Herein lies the principle of our invention.

For washing the hydrochloric-acid gases preferably oils are employed, which essentially consist of h drocarbons. Among other thin the disti lates of the tar from brown coa have been found to be particular lIy suitable.

he method of purifying the h drochloricacid gases may be carrie out, or example, in the followin manner: The hydrochloricacid ases leaving the sulfate-furnace and, need il, freed from water are introduced into "washing-towers, where an oil (for instance,

,an oil produced from brown-coal tar,) 1s

trickled down. In these towers the gases deliver their impurities, particularly also the chlorids of arsenic, to the oil. the gases before their admission to the wash If so required,

in'g-towers may be first passed in a known manner through a filtering layer of porous bodies-for example, reduced charcoal-so that this filter-may retain the greater part of the sulfuric acid and the ferric chlorid. The hydrochloric-acid gas leaving the washingtowers is freed from the impurities to such a degree that the latter (among them also the arsenic) cannot be any more traced or dis- Speci flcatio'n of Letters Patent. Application lllod December 2,1905. Serial No. 289.978-

' through a filter of Patented Nov. 6, 1906.

covered even by the most exact methods, and that this purified gas is at once suitable for the manufacture of chlorin according to Deacon, or when absorbed by'distilled water it will at once yield a chemically-pure hydrochloric acid.

It is obvious that instead of the washingtowers, in which an oil is trickled down, also other known ap aratus may be used in which the gases and t e oils maybe mechanically brought into intimate contact with each oth'erf0r example, exhaustersthrough which the oil is passed and in which. the ases meet a most finelydivided oil, or a comhination of the washing-towers with an exhauster ma be used.

he impurities delivered by the hydrochloric-acid gases therein may be for the most part separated by washing the oil with water, whereupon the oil is ready for repeating its work. Should it be necessary to completely separate the impurities, particularly the arsenic,-from the oil, this may be effected by washing the oil with water, to which a corresponding quantity of caustic lime is added, and afterward so much hydrochloric acid is added to this water as is required for dissolving thacaustic lime. Fatty oils (glycerids) have also the property of absorbing chlorid of arsenic in the like manner as the oils mentioned above, but they offer difliculties in being afterward regenerated or purified by means of water.

Obviously the described method may be employed in all cases where va orous chlorids of arsenic of the mentioned ind are to be separated from other gases or vapors.

What I claim as my invention, and desire to secure by Letters Patent, is-- 1. The process of purifying hydrochloricacid gases, which consists in washing the ases with a mineral oil substantially as and or the purpose described. a

2. The process of purifying hydrochloricacid gases, which consists in washing the gases with a finely-divided mineral oil, substantially as and for the purpose described.

3. The process of purifying hydrochloricacid gases, which consists in assing the gases porous odies and then washing the gases with a mineral oil, substantially as and for the purpose described.

4. The process of purifying hydrochloricacid gases, which consists in passing thrc ugh a filter of porous bodies and then to the oil and accumulated the gases Washing the eral oil, substantially as and for the purpose described. i

5. The process of purifying hydrochloric acid gases, which consists in first washing. the gases with a mineral oil and then washingthe' oil with water substantially as and for the purpose described 6. The process of acid gases, which consists in first washing the gases with a finely-divided-mineral oil and then. washing the oil with water, substantially as and for the purpose described.

7. The

with Water containing caustic lime, and finally adding hydrochloric acid to the water, substantially as and for the purpose described,

8. The process of purifying hydrochloricacid gases, which consists in first washing the.

gases with a finely-divided mineral oil,;then washing the oil with water containing caustic lime, and finally adding hydrochloric acid to the water, substantially as and f th Pup pose described,

9. The process of purifying hydrochloricacid gases, which consists in first passing the gases through a filter of porous material, then washing the gases with a mineral w oil, and

gases with a finely-divided mirh] process of purifying hydrochloricw; acid gases, which consists in first washing the" gases witha mineral oil, thenwashing the oil,

finally washing the .e oil with water substantially as. and-for the purpose described.

10. The process of purifying hydrochloricl acid gases, which consists in-first passing the ,gases-througl ia filter of porous material, then I Washing thegases with a finely-divided min- "eral oil, and finally washing the oil with water I substantially as and for the purpose described. purifying hydrochlorice :;.;.1.L]..= Thesprocess of purifying hydrochloricl, I acid gases, which consists in first passing the l asesr-with a mineral oil, then taining drochloric acidto the purpose described.

In testimony whereof I have signed my name to thisspccifica-tion in the presence of I two subscribing witnesses.

WILHELM HASENBAGH.

Witnesses MAX HARTER, Jos. H. Laura.

withwvater containing caustic porous material, then a finely-divided min ,eral oil, then washing the oil with waterco'ncaustic lime and finally adding hy water, as and for the 

